The major responsibilities of this Core are to perform neuropathoiogic studies necessary to document and fully characterize the diagnostic features of Alzheimer disease (AD) and other neuropathoiogic changes associated with aging and cognitive impairment in brains of ADC subjects who come to autopsy, and to provide suitable tissues for research projects proposed by investigators. Therefore, in Specific Aim 1, we will maintain a bank of human brain tissue from subjects with AD or related dementias, and aged controls. The main functions will be: 1) to collect, prepare, evaluate, catalog, store, and distribute well-characterized postmortem brain tissue and other samples (including postmortem DNA) from deceased demented and control subjects for use in research;2) to report qualitative and quantitative diagnostic information to physicians, families, and researchers;3) to work with the Clinical Core to provide clinico pathologic correlation;and 4) to regularly update the central ADC and National Alzheimer Coordinating Center (NACC) databases with diagnostic and other related information on autopsied subjects. In order to enhance the neuropathoiogic characterization of brain tissue accessioned through this core, we will also focus on providing extensive quantitative neuropathoiogic evaluations for correlation with clinical and research data, including quantification of brain vascular alterations, cerebral white matter density, synapse loss, and neocortical neuritic dystrophy. In Specific Aim 2, we will support investigator-initiated research on aging and neurodegenerative dementias by researchers at UT Southwestern by providing neuropathoiogic data and tissue samples for ongoing and future projects. In Specific Aim 3, we will support multi-institutional studies of aging and neurodegenerative dementias, including LOAD and ADNI, again by providing neuropathoiogic data and tissue samples as necessary.